use new URL()

src/client/js/components/RevisionComparer/RevisionComparer.jsx

@@ -45,8 +45,10 @@ const RevisionComparer = (props) => {
     const { path } = revisionComparerContainer.pageContainer.state;
     const { sourceRevision, targetRevision } = revisionComparerContainer.state;
 
-    const urlParams = (sourceRevision && targetRevision ? `?compare=${sourceRevision._id}...${targetRevision._id}` : '');
-    return encodeSpaces(decodeURI(`${origin}${path}${urlParams}`));
+    const urlParams = (sourceRevision && targetRevision ? `${path}?compare=${sourceRevision._id}...${targetRevision._id}` : '');
+    const url = new URL(urlParams, origin);
+
+    return encodeSpaces(decodeURI(url));
   };
 
   const { sourceRevision, targetRevision } = revisionComparerContainer.state;